Name: cis-2-butene
* IUPAC
CAS Number: 590-18-1
Chemical Formula: C₄H₈ or CH₃CHCHCH₃
Molar Mass: 56.10632 g
Mass Percent: C 85.628 %; H 14.371 % 
Isomers:  1-butene  •  2-methylpropene*  •  cyclobutane*  •  trans-2-butene

• organic

Melting Point:*
-138.9°C 1 = 134.25 K = -218.02°F
Boiling Point:*
3.7°C 2 = 276.85 K = 38.66°F

* - 1 atm pressure

Bonding: polar covalent
Ionic Character: 10.61 %

The heat of combustion is the amount of heat released when one mole of a substance undergoes combustion according to the general reaction equation:
CxHyOz + 0.25(4x+y-2z) O2 (g) → x CO2 (g) + 0.5y H2O (ℓ)

ΔHcomb° (g): -647.79 kcal = -2710.37272 kJ

Wikipedia

(1) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 3-103.
(2) - Estok, George K. Organic Chemistry: A Short Text; W.B. Saunders: Philadelphia, 1959; p 42.
(3) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:68.
(4) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:68.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:68.